1. Field of the Invention
The instant disclosure relates to a solid electrolytic capacitor; in particular, to a solid electrolytic chip capacitor having high yield and reliability and a manufacturing method thereof.
2. Description of Related Art
With the rapid advancement of semiconductor processing technology, packaged electronic products follow the trend of miniaturization, high electrical performance, multi-function, high reliability, and RoHS Compliance. The wet electrolytic capacitor cannot meet the trend requirements of the electronic products, thus the development of the solid state electrolytic capacitor.
There are many different types of substrates that can be used for the solid-state electrolytic capacitor. Currently, aluminum and tantalum are the most commonly used materials for solid-state electrolytic capacitors. To increase capacitance, a plurality of solid-state electrolytic capacitors is laminated together in parallel to form a capacitor unit. Thus, a higher capacitance can be obtained, in which total capacitance is the sum of all values from all capacitor units.
Specifically, when stacking the capacitor units in a packaging process, two anode portions of the adjacent capacitor units are welded to each other. However, the thick anode portion of each capacitor unit almost always results in low welding quality and low welding success rate. Further, the maximum number of the stacked capacitor units is limited by the thick anode portion of each capacitor unit.
Moreover, in the welding process, molten aluminum can be readily produced and splattered when the thick anode portions of the capacitor units are grinded against each other. However, the molten aluminum may occupy only portions of empty space inside the package body after solidification. When the solidifying aluminum is melted twice in a solder reflow process, voids that are formed inside the package body can decrease airtightness. Thus, moisture can enter the package body that may affect electric properties of the capacitor units.